Plate clamp for printing machines



July 6, 1937.

A. LUNDQUIST PLATE CLAMP FOR PRINTING MACHINES Filed Dec. 1, 1955 3Sheets-Sheet 1 a 3W A N E Q a M i A W W mmw Amww f MM July 6, 1937.

A. LUNDQUIST PLATE CLAMP FOR PRINTING MACHINES Filed Dec. 1, 1933 3Sheets-Sheet 2 u 8 W WW Wig 2 k .N. w 4

1 v //////A ////7//A All!- a f \\\\\\\A July 6, 1937. A. LUNDQUIST PLATECLAMP FOR PRINTING MACHINES 3 Sheets-Sheetfi' Filed Dec. 1, 1953 mlvINVENTOR m u L alwziL Patented July 6, 1937 UNlTED STATES PATENT OFFICEPLATE CLAMP FOR PRINTING MACHINES Application December 1, 1933, SerialNo. 700,575

24 Claims.

This invention relates to a plate clamping mechanism for rotary printingmachines and more particularly to an improved form of clamping mechanismwhich employs a smooth acting internal screw to actuate the clampingmechanism.

Various types of plate clamping mechanisms have been devised to lockprinting plates upon a cylinder. In the present invention an improvedarrangement has been provided, whereby clamping members are moved to aplate looking or unlocking position by means of an internal screwthreaded ring which surrounds the cylinder and is rotated by a manuallyactuated tool. Teeth formed on clamp actuating members engage the screwthread of the ring and each member is simultaneously moved when the ringis rotated.

A further feature comprises a pinion gear drive for said ring and ameans for locking the pinion in a set position after the actuating toolhas been removed.

A still further object is the provision or an improved clamp actuatingmember which coopcrates with a spring follow-up means to provide apositive metal to metal contact when the plate clamps are in a clampingposition and utilizing a stored spring pressure of the spring follow-upmeans only when the clamp actuating members become loose as the resultof machine vibration for example.

The invention further consists of certain other novel arrangements andcombinations which will be fully described in connection with theaccompanying drawings and the novel features pointed out in the claimshereunto annexed.

The preferred embodiment of the invention is illustrated in theaccompanying drawings wherein;

Figure l is a cross sectional view through a position;

Figure is a vertical section taken along the line 5 of Figure 1, showinga plate actuating mechanism in a locked position;

Figure 6 is a view similar to Figure 5, but showing a. plate clampactuating mechanism in an.

unlocked position with a tool in a position to actuate the plate clamps;

Figure '7 is a plan detail view looking in the direction of the arrow 1of Figure 5; and

Figure 8 is a plan section taken along the line ways iii in theperipheral surface of the plate cylinder Hi and are provided withbeveled clamp engaging jaws M, which are adapted to be moved intoclamped engagement with beveled edges on the plates ll.

A plate clamp actuating bar 15 is maintained in yieldable engagementwith the clamping member l2 by means of a stud I6, which has a screwthreaded portion I! screwed into a vertically disposed end lB of theclamp actuating bar l5, and a shank portion IS in sliding engagementwith an opening 2|, through a wall 22, in the clamping member l2. A head23 is provided at the end of the shank l9 and is positioned so as toallow a longitudinal movement of the stud within the opening 2L A heavycompression spring 24 is compressed between the end of the cap 23 andthe end of an adjustable screw 25, within a recess 26, and is adapted tonormally maintain the end l8 of the clamp actuating bar in a spacedrelation to the wall 22, when the plates-are in an unlocked conditionsuch as shown in :Figure, 4. When the plate clamp actuating bar I5 ismoved to a plate clamping position, such as from the position shown inFigure 4 to the position shown in Figure 3, the clamp l2 will move inadvance of said actuating bar l5 until the said clamp engages the platell, whereupon a follow-up spring pressure is applied, as the actuatingbar I5 is advanced to contact engagement with the clamp !2. A connectionis thus made. between the. clamp l2 and the actuating bar l5, which asthe bar [5 is moved forward, yields after the clamp l2 engages the platell. When the end of the clamp actuating bar engages the wall 22, thepressure is direct. In the construction as herein discussed, and shownin Figure 1, four clamps simultaneously engage the edge of the plate andare operated by a single mechanism. It will be ob-' served that withthis construction, any variation in the plate length resulting in theengagement of one of the bars I5 coming in contact with its clamp wallin advance of the engagement'ofthe other bars with their correspondingclamps will result in proper clamping of the plate due to the pressureexerted by the springs acting on any clamp or clamps which may not be inactual engagement with their corresponding bars, and should the clampsbecome embedded in the plate during a long run of the machine, thesprings will provide a follow-up pressure which will hold the clamps inclose engagement with the plate.

The several clamping members provided around the periphery of the platecylinder are clearly shown in Figure l, and are divided into two groups,one group for each semi-cylindrical plate. The clamp actuating bars it)are also divided into two individual groups and each group is actuatedindependently of the other to move the corresponding clamping membersinto or away from a plate clamping position. It will be observed whenreferring to Figures 2 and 3 that the clamp actuating bar H5, in Figure2, extends to the end of the plate cylinder and that a clamp actuatingbar M11 in Figure 3 is very much shorter than the bar l5. Each bar 55and Him is provided with gear teeth 21 and Z'ia respectively.

Two rings or ring gears 28 and 29 are arranged over one end of thecylinder l as shown in Figures 2 and 3 on each side of a spacer collar3!, which collar is divided into segments for convenience in assemblingsame, each segment being secured to the cylinder H! by screws 30, asclearly shown in Figure l. The inner ring 29 abuts against a shoulder 32on the cylinder and the outer ring 28 abuts against an end plate 33,which is secured to the end of the cylinder It. Each ring 28, 29 ismounted so as to rotate freely around the cylinder and each has aninternal screw thread 3%, 3 a respectively, which mesh with teeth 2 andZla of the clamp actuating blocks corresponding therewith, the threads34 on the outer ring meshing with the teeth 2? on the clamp actuatingbar l5 and the threads 34a meshing with the teeth 21a on the clampactuating bar l5a. Each ring 28, 29 is also provided with gear teeth 35,35a respectively, which thus converts same into a form of bevel gear.

Referring to Figures 5 and 6, the means for rotating the rings 28 and 29will now be described. A bevel pinion 36 meshes with the ear teeth 35aon the ring 29 and is rotatably mounted in the spacer collar 3i. A lowerprojecting end or extended hub portion 38 of said pinion is rotatablymounted within a sleeve 3?, said sleeve being mounted in a recess 39within the cylinder iii. A plunger 45 is slidably mounted beneath thelower end 38 of the pinion gear 35 within a recess (i2 and has a reducedend 43 which is also slida ly mounted in a recess 45. A compressionspring positioned around the reduced end 3 of the plunger, will forcethe plunger upward and hold a ratchet toothed face on the upper end 56of the plunger in clutched engagement with a similar ratchet toothedface #3? on the lower end 38 of the pinion 36. Slots lil, 48 are cutinto the cylinder ll] adjacent the recess i2, within which theprojecting ends of a pin 49 are guided, said pin being mounted in thehead of the plunger 4 I.

With the parts in the position shown in Figure 5, the pinion 35 ispositively locked against any rotation, due to the clutched engagementof the ratchet toothed faces 46 and ll of the plunger 4! and the lowerend 38 of the pinion, and also due to the engagement of the ends of apin 69 with slots 48 in the end 38 which prevent the plunger fromrotating. Such positions will correspond with either a locked or anunlocked plate position.

In Figure 1 it will be observed that two pinions 36, 36a are provided,each being the same in structure but arranged in driving relation sothat one will drive the ring 28 and the other will drive the ring 29.

- When it is desirable to move the plate clamps l2 into or out ofclamped engagement with the plates H, a tool, having a square shank 52,is inserted into a similarly shaped socket 53 in the pinion 36 and whenrotated, will cause the pinion to rotate one of the rings 29 or 30.

Means is provided to release the clutched ratchet portions 4% and 4? atthe lower end of the pinion and the upper end of the plunger when thetool is inserted in the pinion. Said means comprises two balls 54, Mwhich are guided within a slot 55, cut through the lower end 38 of thepinion 35, and engage beveled ends 56, 55 of two pins 57, all said pinsbeing slidably mounted in the lower end 38 of the pinion 36 and havingtheir beveled ends 56, 56 projecting into the slot 55. A hardened steelplate 58 is also secured to the lower ends of the pins 51, 5'! and isslidable therewith. Another ball 59 is loosely mounted within a recess5i in the upper end of the plunger ll directly beneath the plate 58.

As the tool 5| is inserted in the pinion 36, a cone pointed end 62, atthe end of a neck 63 and below the shank 52, will wedge between theballs 55 to separate same and to permit said neck portion E53 to bemoved into engagement with the balls and thus force same to the positionshown in Figure 6. During the outward movement of the balls E l, theywill cam the pins 57, 5'! downward and thus cause the plate 58 at theend thereof to engage and force the ball 59 downward, which action willcause the plunger Al to be moved therewith and thereby release theratchet teeth 46 on the plunger from their clutched engagement with theteeth 31 on the lower end 33 of the pinion 36. Having been released inthis manner, the pinion is then free to be rotated.

The general operation considered in conjunction with Figures 3 and 5 isas follows:

After having placed the plates II in position on the plate cylinder Ill,the operator will insert an actuating tool in the socket 53 of thepinion 36, whereupon the said gear is free to be rotated. Upon therotation of same, the engagement of the gear teeth 35a on the ring 29with the pinion, will cause the ring to be rotated. Therefore since theteeth 21a on the clamp actuating bars lEa mesh with the screw 35a, thesaid clamp actuating bars will be moved forward and will push the plateclamp l2 with its yieldable spring connection ahead of it. After theclamp engages the plate, the movement of the bar Him is still continuedto apply a yieldable clamping pressure through the spring 24.

A smooth sliding movement is thereby applied to the clamps and actuatingbars, an individual spring follow-up pressure is applied to the clampsand the arrangement of the parts provides 'a generally smooth andsymmetrical outer appearance with no parts projecting beyond theexterior of the cylinder.

While the invention has been shown and described in its preferred form,it will be understood that certain changes and variations may be made inthe specific structure provided for carrying out the invention, withouthowever departing from the spirit of the invention as defined in theappended claims. a

J member What I claim is:

1. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of an internal screw, a clamp actuating inoperative engagement with said screw, and a manually actuated drive torotate said screw.

2. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring having an internal screw thereon coaxialwith said cylinder, clamp actuating members in operative engagement withsaid screw, and manually actuated means for rotating said ring, wherebythe plate clamps are simultaneously moved to or from a plate clampingposition.

3. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring having an internal screw thereon coaxialwith said cylinder, clamp actuating members in operative engagement withsaid screw, a manually actuated means to rotate said ring, and means tolock the plate clamps in a plate clamping position.

4. The combination with a plate holding cylinder having longitudinallymovable plate clamp actuating bars having toothed portions in and havingan internal screw portion thereon, clamp actuating bars having toothedportions in mesh with the internal screw, and manually actuated means torotate said ring, whereby the plate clamps are simultaneously moved toand from a plate clamping position.

5. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring rotatable around the cylinder and havingan internal screw thereon, yieldable plate clamp actuating bars adaptedto be moved by the rotation of said ring, and a manually actuated meansto rotate said ring.

6. The combination with a plate holding cylinder having longitudinallymovable clamps, of a ring rotatable around the cylinder and having aninternal screw portion, yieldable plate clamp actuating bars havingtoothed portions in mesh with the screw, and manually actuated means torotate said ring.

7. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring gear rotatable around the cyl inder andhaving an internal screw portion, clamp actuating members in operativeengagement with said screw, and a manually actuated pinion in mesh withsaid ring gear.

8. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring gear rotatable around the cylinder andhaving an internal screw portion, clamp actuating members in operativeengagement with said screw, a pinion in mesh with said ring gear, andmeans to lock said pinion against rotation when the plates are clamped.

9. The combination with a plate holding cylinder of plate holding clampslongitudinally movable thereon, bars movable with said clamps andyieldable connections between said bars and clamps, a ring having aninternalthread portion positioned around the cylinder and in a drivingrelation with the bars, and a means for rotating the ring, whereby'thebars and clamps are simultaneously movable to and from a plate clampingposition.

10. The combination with a plate holding cylinder of plate holdingclamps longitudinally movable thereon, a ring rotatable around thecylinder plate and having an internal screw thereon, bars connected in adriving relation with said screw, yieldable connections between the barsand plate clamps comprising a pluralityoi springs compressed to normallyhold the bars and plate clamps spaced apart and adapted to be furthercompressed after the plate clamps engage f-the plate, and means torotate the rotatable ring, whereby the bars are driven in a forward or arearward direction.

11. In a device for clamping stereotype plates on a printing cylinder,comprising plate clamps, a ring gear rotatable around the cylinderhaving an internal screw threaded portion, a clamp actuating member inoperative relation with said screw thread, and a manually actuatedpinion to rotate said ring gear.

12. The combination with a plate holding cylinder having longitudinallymovable plate clamps thereon, of clamp actuating bars, means forsimultaneously moving said bars to a plate clamping position, a springfollow-up connection between said bars and clamps which is yieldable topermit each bar to move into direct contact with the plate clamp, and tomaintain a continu ous spring pressure upon the plate clamp if anyseparation between a bar and clamp should ocour.

13. In a mechanism for clamping printing plates upon a cylinder, aperipherally movable operating member, longitudinally movable clampactuating members, plate clamps simultaneously movable with said clampactuating members, and yieldable means interposed between the said clampactuating members and the clamps, whereby said clamping members areadapted to be moved into direct contact with the clamps under normalplate clamping conditions.

14. In a mechanism for clamping printing plates upon a cylinder, aperipherally movable member, clamp actuating bars longitudinally movablealong said cylinder, plate clamps simultaneously movable with said bars,and spring tensioning means interposed between the bars and the clamps,whereby said clamping members are adapted to be moved into directcontact with the clamps under normal plate clamping conditions.

15. The combination with a plate holding cylinder having longitudinallymovable plate clamps, of a ring having a screw on a cylindrical surfacethereof coaxial with the cylinder, clamp actuating members in operativeengagement with the screw, and means for rotating saidring,

whereby the plate clamps are simultaneously moved to or from a plateclamping position.

16. In a device for clamping plates to a printing cylinder, a movableplate clamp, a slidably mounted member to move said clamp into clampingengagement with a plate, a rotatable ring, means comprising threads onone and teeth on the other, connecting said member with said ring,whereby rotation of said ring willactuate said clamp moving member tomove said clamp, a rotatable member drivingly connected to said ring torotate. the same, and an operating memwhereby rotation of said ring willactuate said clamp moving member to move said clamp, a rotatable memberdrivingly connected to said ring to rotate the same, releasable lockingmeans to prevent rotation of said ring by said rotatable member, and anoperating member for said rotatable member; said operating member beingremovably engageable with said locking means and with said operatingmember and operable to actuate both when engaged therewith, to releasethe former and to rotate the latter.

18. In a device for clamping a stereotype plate on a printing cylinder,a plate clamp, a clamp actuating member,- a ring gear rotatable to causesaid member to actuate said clamp, said member and said ring gear havinga plurality of cooperating teeth and threads to operably connect thesame, a driving pinion to rotate said ring gear, and a manually actuatedmember removably engageable with said pinion to rotate the same whenengaged therewith.

19. In a device for clamping a stereotype plate on a printing cylinder,a plate clamp, a clamp actuating member, a ring gear rotatable to causesaid member to actuate said clamp, said member and said ring gear havingcooperating teeth and threads to operably connect the same, a drivingpinion to rotate said ring gear, a releasable looking means operablewhen in locked position to prevent ring gear rotation by said pinion,said locking means including an axially slidable member mounted on theaxis and in the hub of said pinion, non-rotatable means to engage saidmember to lock it against rotation, and a manually actuated memberremovably engageable with said locking means and with said pinion torelease the former and actuate the latter when in engaged relation withboth.

20. Mechanism for clamping a stereotype plate to a printing cylinder,comprising a longitudinally movable plate clamp, a slidable clampactuating member, means including cooperating rotatable members to slidesaid member to move said clamp into and out of plate clamping position,one of said rotatable members being threadingly connected to saidmember, releasable looking means for one of said rotatable members toprevent operation thereof to move said clamp, and an operating memberfor releasing said looking means and to move the lockable rotatablemember.

21. Mechanism for clamping a stereotype plate to a printing cylinder,comprising a longitudinally movable plate clamp, a slidable clampactuating member, means including cooperating rotatable members to slidesaid member to move said clamp into and out of plate clamping position,one of said rotatable members being threadingly connected to saidmember, and a member removably engageable with one of said rotatablemembers to actuate the same when engaged therewith.

22. In a device for clamping a plate to a cylinder, a movable plateclamp, means to move the clamp into plate clamping position including aslidably mounted member, a rotatable ring, cooperating teeth and threadsbetween said member and said ring whereby rotation of said ring willmove said member and a rotatable pinion adapted to rotate said ring,said pinion having a hub portion, an axially slidable member on said hubportion, a non-rotatable part, and releasable cooperating means betweensaid slidable member and said part to lock said pinion to said part.

23. In a device for clamping a plate toa cylinder, a movable plateclamp, means to move the clamp into plate clamping position including aslidably mounted member, a rotatable ring, cooperating teeth and threadsbetween said member and said ring whereby rotation of said ring willmove said member and a rotatable pinion, said pinion having a hubportion, an axially slidable member on said hub portion, a non-rotatablepart, and releasable cooperating means between said axially slidablemember and said part to lock said pinion to said part, and an operatingmember removably engageable with said pinion and operably engageablewith said member to release said locking means and rotate said pinion.

24. In a device for clamping a plate to a cylinder, a movable plateclamp, means to move the clamp into plate clamping position including aslidably mounted member, a rotatable ring, cooperating teeth and threadsbetween said member and said ring whereby rotation of said ring willmove said member and a rotatable pinion, said pinion having a hubportion, said hub portion journaled in said cylinder, an axiallyslidable member in said hub portion, a part mounted in said cylinder,means to retain said part against rotation, cooperating means betweensaid axially slidable member and said part to releasably conmeet thesame to lock said pinion to said part, and an operating member removablyengageable with said pinion to rotate the same, said operating memberwhen in pinion operating position being adapted to release said partfrom looking connection with said axially slidable member.

ARVID LUNDQUIST.

